One of the eleven holy days on the Baha'i calendar, this day marks the Birth of Bab ud-Din (Mirza Ali Muhammad), who declared himself a Prophet of God. Born in 1819 in Shiraz, Iran, his mission was to reform Islam, and his teachings became the foreground for the later developed Baha'i tradition. Baha'is celebrate this day with gatherings to pray, eat together, and read about his life.